ASTM International Committee F39 on Normal and Utility Category Airplane Electrical Wiring Systems has approved its first standard, F 2490, Guide for Aircraft Electrical Load and Power Source Capacity Analysis. The new guide covers how to prepare an electrical load analysis to meet Federal Aviation Administration requirements.

“This standard is a model for a consistent method of determining the state of a small airplane’s electrical system capacity,” says Barry Ballenger, aerospace engineer, Small Airplane Directorate, Federal Aviation Administration. “This is not only important for initial design considerations but also throughout the life of the aircraft.” Ballenger notes that many aircraft are modified over their lives and that any modification must show that additional electrical loads will meet the design requirements of the manufacturer’s type design.

According to Ballenger, F 2490 will provide acceptable methods of meeting the requirements of Federal Aviation Regulation 23.1351(a), which states that normal, utility and acrobatic airplanes must show that their electrical systems are adequate for their intended use and safe operation. The regulation states that either an electrical load analysis or electrical measurements can be used to show compliance. The new standard describes procedures for both analysis and measurement methods.

In addition to being an important tool for compliance issues, F 2490 will be helpful when modifying an airplane’s type design. Ballenger says that whether modification approval is by the supplemental type certificate process or the field approval process, F 2490 can be used to show any modification affecting the electrical system remains within type design requirements.

“By providing a standard method of electrical system load analysis, safer airplanes can be produced and operated,” says Ballenger. “It is the intent of this standard to make general aviation safer and more efficient.”

Committee F39 is actively soliciting industry involvement in the development of future standards. “With the growing reliance on aircraft electrical and electronic systems, it is imperative that the industry has modern design and operational standards for these systems,” says Ballenger.